/// <summary>
/// 图片操作：生成缩略图、添加水印、截取图片等
/// </summary>
public class ImagesHelper
{
/// <summary>
/// 根据文件流获得图片宽度
/// </summary>
/// <param name="file"></param>
/// <returns></returns>
public static int getImgWidth(Stream stream)
{
Image img = Image.FromStream(stream);
int result = img.Width;
img.Dispose();
stream.Dispose();
return result;
}
/// <summary>
/// 根据图片路径获得图片宽度
/// </summary>
/// <param name="filePath"></param>
/// <returns></returns>
public static int getImgWidth(string filePath)
{
Image img = Image.FromFile(filePath);
int result = img.Width;
img.Dispose();
return result;
}
#region 从文件流生成缩略图
/// <summary>
/// 从文件流生成缩略图
/// </summary>
/// <param name="stream">数据IO流</param>
/// <param name="savePath"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="scale"></param>
/// <returns></returns>
public static bool GetThumbNail(Stream stream, string savePath, int width, int height, ThumbNailScale scale)
{
//缩略图
Image img = Image.FromStream(stream);
stream.Dispose();
int towidth = width;
int toheight = height;
int x = 0;
int y = 0;
int ow = img.Width;
int oh = img.Height;
//如果图片小于指定宽度
if (ow < width)
width = ow;
if (oh < height)
height = oh;
switch (scale)
{
case ThumbNailScale.Appointed:
break;
case ThumbNailScale.ScaleWidth:
toheight = img.Height * width / img.Width;
break;
case ThumbNailScale.ScaleHeight:
towidth = img.Width * height / img.Height;
break;
case ThumbNailScale.Cut:
if ((double)img.Width / (double)img.Height > (double)towidth / (double)toheight)
{
oh = img.Height;
ow = img.Height * towidth / toheight;
y = 0;
x = (img.Width - ow) / 2;
}
else
{
ow = img.Width;
oh = img.Width * height / towidth;
x = 0;
y = (img.Height - oh) / 2;
}
break;
case ThumbNailScale.ScaleDown:
double Tw, Th;
Tw = width;
Th = height * (Convert.ToDouble(oh) / Convert.ToDouble(ow));
if (Th > height)
{
Th = height;
Tw = width * (Convert.ToDouble(ow) / Convert.ToDouble(oh));
}
towidth = Convert.ToInt32(Tw);
toheight = Convert.ToInt32(Th);
break;
default:
break;
}
//新建一个bmp图片
Image bitmap = new Bitmap(towidth, toheight);
//新建一个画板
Graphics g = Graphics.FromImage(bitmap);
//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空画布并以透明背景色填充
g.Clear(Color.Transparent);
//在指定位置并且按指定大小绘制原图片的指定部分
g.DrawImage(img, new Rectangle(0, 0, towidth, toheight),
new Rectangle(x, y, ow, oh),
GraphicsUnit.Pixel);
try
{
//以jpg格式保存缩略图
bitmap.Save(savePath, ImageFormat.Jpeg);
}
catch (Exception ex)
{
Logger.Write(string.Format("从文件流生成缩略图：{0}", ex.Message), Logger.MsgType.Error);
return false;
}
finally
{
img.Dispose();
bitmap.Dispose();
g.Dispose();
}
return true;
}
#endregion
#region 从文件路径生成缩略图
/// <summary>
/// 从图片路径生成缩略图
/// </summary>
/// <param name="originalImagePath">图片路径</param>
/// <param name="savePath">保存路径</param>
/// <param name="width">缩略图宽度</param>
/// <param name="height">缩略图高度</param>
/// <param name="mode">HW:指定高宽缩放（可能变形） W://指定宽，高按比例 H://指定高，宽按比例 Cut://指定高宽裁减（不变形） </param>
/// <returns></returns>
public static bool GetThumbNail(string originalImagePath, string savePath, int width, int height, ThumbNailScale scale)
{
//缩略图
Image img = Image.FromFile(originalImagePath);
int towidth = width;
int toheight = height;
int x = 0;
int y = 0;
int ow = img.Width;
int oh = img.Height;
//如果图片小于指定宽度
if (ow < width)
width = ow;
switch (scale)
{
case ThumbNailScale.Appointed:
break;
case ThumbNailScale.ScaleWidth:
toheight = img.Height * width / img.Width;
break;
case ThumbNailScale.ScaleHeight:
towidth = img.Width * height / img.Height;
break;
case ThumbNailScale.Cut:
if ((double)img.Width / (double)img.Height > (double)towidth / (double)toheight)
{
oh = img.Height;
ow = img.Height * towidth / toheight;
y = 0;
x = (img.Width - ow) / 2;
}
else
{
ow = img.Width;
oh = img.Width * height / towidth;
x = 0;
y = (img.Height - oh) / 2;
}
break;
case ThumbNailScale.ScaleDown:
double Tw, Th;
Tw = width;
Th = height * (Convert.ToDouble(oh) / Convert.ToDouble(ow));
if (Th > height)
{
Th = height;
Tw = width * (Convert.ToDouble(ow) / Convert.ToDouble(oh));
}
towidth = Convert.ToInt32(Tw);
toheight = Convert.ToInt32(Th);
break;
default:
break;
}
//新建一个bmp图片
Image bitmap = new Bitmap(towidth, toheight);
//新建一个画板
Graphics g = Graphics.FromImage(bitmap);
//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空画布并以透明背景色填充
g.Clear(Color.White);
//在指定位置并且按指定大小绘制原图片的指定部分
g.DrawImage(img, new Rectangle(0, 0, towidth, toheight),
new Rectangle(x, y, ow, oh),
GraphicsUnit.Pixel);
try
{
//以jpg格式保存缩略图
bitmap.Save(savePath, ImageFormat.Jpeg);
}
catch (Exception e)
{
throw e;
}
finally
{
img.Dispose();
bitmap.Dispose();
g.Dispose();
}
return true;
}
#endregion
#region 获取图片格式
/// <summary>
/// 获取图片格式
/// </summary>
/// <param name="strContentType"></param>
/// <returns>返回图片格式</returns>
public static ImageFormat GetImageType(object strContentType)
{
if ((strContentType.ToString().ToLower()) == "image/pjpeg")
{
return ImageFormat.Jpeg;
}
else if ((strContentType.ToString().ToLower()) == "image/gif")
{
return ImageFormat.Gif;
}
else if ((strContentType.ToString().ToLower()) == "image/bmp")
{
return ImageFormat.Bmp;
}
else if ((strContentType.ToString().ToLower()) == "image/tiff")
{
return ImageFormat.Tiff;
}
else if ((strContentType.ToString().ToLower()) == "image/x-icon")
{
return ImageFormat.Icon;
}
else if ((strContentType.ToString().ToLower()) == "image/x-png")
{
return ImageFormat.Png;
}
else if ((strContentType.ToString().ToLower()) == "image/x-emf")
{
return ImageFormat.Emf;
}
else if ((strContentType.ToString().ToLower()) == "image/x-exif")
{
return ImageFormat.Exif;
}
else if ((strContentType.ToString().ToLower()) == "image/x-wmf")
{
return ImageFormat.Wmf;
}
else
{
return ImageFormat.MemoryBmp;
}
}
#endregion
/// <summary>
/// 生成水印图片
/// </summary>
/// <param name="sourceFile"></param>
/// <param name="saveFile">保存文件路径</param>
/// <returns></returns>
public static bool MakeWaterImage(Stream sourceFile, string saveFile)
{
bool result = false;
//水印图片
try
{
Image imgPhoto = Image.FromStream(sourceFile);
sourceFile.Close();
sourceFile.Dispose();
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Image imgWatermark = new Bitmap(System.Web.HttpContext.Current.Server.MapPath("/images/watermark.png"));
int wmWidth = imgWatermark.Width;
int wmHeight = imgWatermark.Height;
if (phWidth > (wmWidth + 100) && phHeight > (wmHeight + 100))
{
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, phWidth, phHeight), 0, 0, phWidth, phHeight, GraphicsUnit.Pixel);
grPhoto.Dispose();
//添加水印图片
using (Bitmap bmWatermark = new Bitmap(bmPhoto))
{
bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Graphics grWatermark = Graphics.FromImage(bmWatermark);
using (ImageAttributes imageAttributes = new ImageAttributes())
{
//ColorMap colorMap = new ColorMap();
//colorMap.OldColor = Color.FromArgb(255, 255, 255,255);
//colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
//ColorMap[] remapTable = { colorMap };
//imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
float[][] colorMatrixElements = { new float[] { 1.0f, 0.0f, 0.0f, 0.0f, 0.0f }, new float[] { 0.0f, 1.0f, 0.0f, 0.0f, 0.0f }, new float[] { 0.0f, 0.0f, 1.0f, 0.0f, 0.0f }, new float[] { 0.0f, 0.0f, 0.0f, 1.0f, 0.0f }, new float[] { 0.0f, 0.0f, 0.0f, 0.0f, 1.0f } };
ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
int xPosOfWm = ((phWidth - wmWidth) - 2);
int yPosOfWm = ((phHeight - wmHeight) - 2);
grWatermark.DrawImage(imgWatermark, new Rectangle(xPosOfWm, yPosOfWm, wmWidth, wmHeight), 0, 0, wmWidth, wmHeight, GraphicsUnit.Pixel, imageAttributes);
}
imgPhoto = bmWatermark;
grWatermark.Dispose();
imgPhoto.Save(saveFile, ImageFormat.Jpeg);
}
result = true;
}
else
{
result = false;
}
imgWatermark.Dispose();
bmPhoto.Dispose();
imgPhoto.Dispose();
}
catch(Exception ex)
{
Logger.Write(string.Format("生成水印图片错误:{0}",ex.Message), Logger.MsgType.Information);
try
{
Image imgPhoto2 = Image.FromStream(sourceFile);
imgPhoto2.Save(saveFile, ImageFormat.Jpeg);
imgPhoto2.Dispose();
result = true;
}
catch
{
result = false;
}
}
return result;
}
/// <summary>
/// 生成水印图片
/// </summary>
/// <param name="sourceFile"></param>
/// <param name="saveFile">保存文件路径</param>
/// <param name="Location">位置 0 - 右下角 1 - 居中 2 - 右上角 3 - 左下角</param>
/// <returns></returns>
public static bool MakeWaterImage(Stream sourceFile, string saveFile, ImagePosition Position)
{
bool result = false;
//水印图片
try
{
Image imgPhoto = Image.FromStream(sourceFile);
int phWidth = imgPhoto.Width;
int phHeight = imgPhoto.Height;
Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);
bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Image imgWatermark = new Bitmap(System.Web.HttpContext.Current.Server.MapPath("/images/watermark.png"));
int wmWidth = imgWatermark.Width;
int wmHeight = imgWatermark.Height;
if (phWidth > (wmWidth + 100) && phHeight > (wmHeight + 100))
{
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, phWidth, phHeight), 0, 0, phWidth, phHeight, GraphicsUnit.Pixel);
grPhoto.Dispose();
//添加水印图片
using (Bitmap bmWatermark = new Bitmap(bmPhoto))
{
bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);
Graphics grWatermark = Graphics.FromImage(bmWatermark);
using (ImageAttributes imageAttributes = new ImageAttributes())
{
//ColorMap colorMap = new ColorMap();
//colorMap.OldColor = Color.FromArgb(255, 255, 255,255);
//colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
//ColorMap[] remapTable = { colorMap };
//imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
float[][] colorMatrixElements = { new float[] { 1.0f, 0.0f, 0.0f, 0.0f, 0.0f }, new float[] { 0.0f, 1.0f, 0.0f, 0.0f, 0.0f }, new float[] { 0.0f, 0.0f, 1.0f, 0.0f, 0.0f }, new float[] { 0.0f, 0.0f, 0.0f, 1.0f, 0.0f }, new float[] { 0.0f, 0.0f, 0.0f, 0.0f, 1.0f } };
ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
int xPosOfWm = 0;
int yPosOfWm = 0;
switch (Position)
{
case ImagePosition.BottomRight:
xPosOfWm = ((phWidth - wmWidth) - 2);
yPosOfWm = ((phHeight - wmHeight) - 2);
break;
case ImagePosition.TopLeft:
xPosOfWm = 2;
yPosOfWm = 2;
break;
case ImagePosition.TopRigth:
xPosOfWm = ((phWidth - wmWidth) - 2);
yPosOfWm = 2;
break;
case ImagePosition.BottomLeft:
xPosOfWm = 2;
yPosOfWm = ((phHeight - wmHeight) - 2);
break;
case ImagePosition.Center:
xPosOfWm = ((phWidth / 2) - (wmWidth / 2));
yPosOfWm = ((phHeight / 2) - (wmHeight / 2));
break;
}
grWatermark.DrawImage(imgWatermark, new Rectangle(xPosOfWm, yPosOfWm, wmWidth, wmHeight), 0, 0, wmWidth, wmHeight, GraphicsUnit.Pixel, imageAttributes);
}
imgPhoto = bmWatermark;
grWatermark.Dispose();
imgPhoto.Save(saveFile, ImageFormat.Jpeg);
}
result = true;
}
else
{
Image imgPhoto2 = Image.FromStream(sourceFile);
imgPhoto2.Save(saveFile, ImageFormat.Jpeg);
imgPhoto2.Dispose();
result = true;
}
imgWatermark.Dispose();
bmPhoto.Dispose();
imgPhoto.Dispose();
}
catch
{
try
{
Image imgPhoto2 = Image.FromStream(sourceFile);
imgPhoto2.Save(saveFile, ImageFormat.Jpeg);
imgPhoto2.Dispose();
result = true;
}
catch
{
result = false;
}
}
sourceFile.Close();
sourceFile.Dispose();
return result;
}
#region 从图片中截取一张指定大小的图片
/// <summary>
/// 从图片中截取部分生成新图
/// </summary>
/// <param name="sFromFilePath">原始图片</param>
/// <param name="saveFilePath">生成新图</param>
/// <param name="width">截取图片宽度</param>
/// <param name="height">截取图片高度</param>
/// <param name="spaceX">截图图片X坐标</param>
/// <param name="spaceY">截取图片Y坐标</param>
public static void CaptureImage(string sFromFilePath, string saveFilePath, int width, int height, int spaceX, int spaceY)
{
//载入底图
Image fromImage = Image.FromFile(sFromFilePath);
int x = 0; //截取X坐标
int y = 0; //截取Y坐标
//原图宽与生成图片宽 之差
//当小于0(即原图宽小于要生成的图)时，新图宽度为较小者 即原图宽度 X坐标则为0
//当大于0(即原图宽大于要生成的图)时，新图宽度为设置值 即width X坐标则为 sX与spaceX之间较小者
//Y方向同理
int sX = fromImage.Width - width;
int sY = fromImage.Height - height;
if (sX > 0)
{
x = sX > spaceX ? spaceX : sX;
}
else
{
width = fromImage.Width;
}
if (sY > 0)
{
y = sY > spaceY ? spaceY : sY;
}
else
{
height = fromImage.Height;
}
//创建新图位图
Bitmap bitmap = new Bitmap(width, height);
//创建作图区域
Graphics graphic = Graphics.FromImage(bitmap);
//截取原图相应区域写入作图区
graphic.DrawImage(fromImage, 0, 0, new Rectangle(x, y, width, height), GraphicsUnit.Pixel);
//从作图区生成新图
Image saveImage = Image.FromHbitmap(bitmap.GetHbitmap());
//保存图象
saveImage.Save(saveFilePath, ImageFormat.Jpeg);
//释放资源
saveImage.Dispose();
bitmap.Dispose();
graphic.Dispose();
}
#endregion
public enum ImagePosition
{
/// <summary>
/// 居中
/// </summary>
Center,
/// <summary>
/// 左上角
/// </summary>
TopLeft,
/// <summary>
/// 左下角
/// </summary>
BottomLeft,
/// <summary>
/// 右下角
/// </summary>
BottomRight,
/// <summary>
/// 右上角
/// </summary>
TopRigth
}
/// <summary>
/// 图片
/// </summary>
public enum ThumbNailScale
{
/// <summary>
/// 指定高宽缩放，图片长宽不一致会变形
/// </summary>
Appointed,
/// <summary>
/// 指定宽，高按比例
/// </summary>
ScaleWidth,
/// <summary>
/// 指定高，宽按比例
/// </summary>
ScaleHeight,
/// <summary>
/// 指定高宽裁减，可能只显示部分图片
/// </summary>
Cut,
/// <summary>
/// 按图片比例缩放，不变形，显示全部图片（推荐）
/// </summary>
ScaleDown
}
}
